Dredging machine



\ o. B. PERRY DREDGING MACHINE June 10, 1930.

Filed Nov. 7, 1928 1"l' '1 I W A 3 Sheets-Sheet 1 ATTORNEYS.-

June 10, 1930. Q PERRY 1,762,794

DREDGING MACHINE Filed Nov. 7, 1928 3 Sheets-Sheet v 2 v INVENTOR:OscamBi-hr/y A TI'ORNE YS.

- June 10, 1930. 0. 1 3. F ERRY 1,762,794

DREDG ING MACHINE Filed Nbv. 7, 1928 s Sheets-Sheet 5 INVENTOR. carB.Perqy A TIORNE S.

Patented June 10, 1930 r UNITED STATES PATENT OSCAR B. PERRY, OF SANFRANCISCO, CALIFORNIA DEEDGING MACHINE Applic'atioiifiled November 7,1928. Serial No. 317,758. i

This invention relates generally to the pear from the. followingdescription in construction of dredging machines, particuwhich I haveset forth'the'preferred embodilarly 'to machines of this character whichment of my invention. It is to be underare employed for the dredging ofminerals stoodthat the appended claims are to be such as gold or tin.accorded a range of equivalents consistent 55 The usual form of dredgingmachine of the with the state of the prior art. type to which thisinvention relates utilizes Referring to the drawing:

a suitable supporting structure, such as a Figure 1 is a sideelevationalviewshowbarge, tov which is adjustably secured an mg a machineincorporating my invention,

extended ladder carrying a digging bucket and lllustrating the manner inwhich it op- 60 line.- The ladder. is frequently co'mp'aracrates upon aformation being dredged. tively long and extends downwardly at an 'F1g.2 is a diagrammatic side elevational angle to the surface ofthe'formation being V ew Illustra ing the bucket line of a I dredged.The bucket line, which consists dredge r supported maccordance with thisof a seri f dig i b k t li k d t mventlon, the ladder being shown in two65 gether, is entrained over an idler tumbler P f at the lower'endof'the ladder, and over a g- 3 1 a ctall illustrating in side eledrivingtumbler at the upper end. The slack vatlcn the 1 1 1 pulley Which Iincorporate portion of the bucket line in ordinary i i my uPp0rt1ngladder. Y I

d dg i b t nti ll u p t d except Flg. 4 1s a cross sect10nalv1ew takenalong 70 for idlers which may be mounted upon the t 1 116 of Flg. 3. Ibarge near the upper end of the ladder. As n y Inven ion I utilize anidler wheel a result considerable strain and wear is im- Whi h isiournaled directly to the ladder of posed upon the interconnecting linksand dredging machine at a point substantially pins of the buckets and ifthe ladder is of midway between the ends of the same. 75 at l th th t aimay b om Preferably theladder is made of a pair of cessive or evenprohibitive, It is therestructural members and the idler wheel is foreone object of this invention to substanm n ed so as to be positionedbetween Su h tially relieve such strains by supporting the members. IGuide rollers are cooperatively slack side of thebucket line in a novelmanassociated With the idler wheel, and the slack 80 ner, and at thesame ti e to mak practical portionof the bucket'line is entrained overlonger ladders for digging at greater depths. "this Wheel and guided inplace'by suitable In dredging over uneven bedrock characolle s. hus re eri g to e, d wi g I terized by sharp pinnacles,- such as encounhave:shown a dredging machine utilizing tered in Malaya, it is difficult toproperly a supporting barge 10 upon which is mount- 85 remove thevaluable mineral from between ed an extended ladder 11. By means of athe pinnacles with ordinary dredgers as the cable 12, the ladder can beraisedor lowered slack portion of the bucket line tends to loop to anydepth desired. Carried by the ladder, over and catch upon the pinnacles.'It is there is an'endless bucket. line 13 which is r 40 therefore afurther object of this invention entrained about a tumbler 14 journaledto 90 to support the slack portion of thegbucket the lower end ofladder'll, and also'about line in such amanner that dredging of thisdriving tumbler 16 journaled near the upcharacter is facilitated." r perend of the ladder. Tumbler 16 is driven It is another object of thisinvention to in any suitable way as by means of driving devise a novelarrangement of an idler wheel gears 17 so as to tension theupper'portion s5 for supporting the slack side of a dredging of thebucket'line.

bucket line, and to devise 'novel means-for When the lower portion orslack side of properly guiding the bucket line upon the such a bucketline is unsupported, jexcept idler. Y r possibly by an idler mountedupon the barge Further obiects 0f theinvention will aplO'near-thedrivingtumbler 16, the lower 1 0 portion of the bucket line sags down along acatenary curve, such as indicated at 21 in Fig. 2. When the ladder is ina lowered position as during digging operations, the slack side stillsags down considerably as indicated by line 21 Since the buckets ofthese lines are comparatively heavy, it is apparent that the weight (ifthe slack portion of the line adds greatly to the strain and wear uponthe interconnecting link's'and pins of the buckets, tllllS causingfrequent breakage and repairs. Furthermore such strains increaseenormously with "an increase in the length of adredgin ladder, thusimposing a practical limit to tie depth of operation. Furthermore whenit is attempted .to operate themachine over uneven bedrock characterizedby one or more pinnacles 22, it is obvious that if the lower end of theladder :is moved close to .a pinnacle in order to remove valuableminerals, the sag of the line may permit the buckets to droop over thetop of the pinnacle, thus causing the buckets to catch upon the rockformation. L

As :has been previously outlined, my invention I provide an idler wheel23 which is journaled tothe ladder l1 and is preferably positionedsubstantially midway between the ends thereof. The construction of thisidler wheel and its cooperative guide rollers is shown more cleanly inFigs. *3 and 4. I prefer to construct the ladder ll of two spacedparallel structural members 24, which are secured together in anysuitable manner to form a unitary structure. Bearings 26 are mountedupon the lower edges 'of structural members 2st to provide a journal forthe shaft 27 of the idler whee-l The Y bucket line which I employutilizes metal buckets 28 linked together by means of pins 29, andthedigging edges 31 of the buckets are preferably curved as shown in Fig3. The lower portion ofthe bucket line is extended into the ladderbetween the structural members "24 and is looped over orentrained uponthe periphery of idler wheel 23-. In order to form a more effectiveengagement and to guide the bucket line upon the idler wheel, theperiphery 32 of the idler wheel is preferably concaveto fit phe curveddigging edges =31 as shown in i .4.

in "addition to -the idler wheel 23 I also preferably provide .guidingmeans the form of rollers 33 which are preferably mounted upon the innersides of structural members 24 by means of suitable bearing blocks 34-.Guide rollers 33 are positioned a iacent to the idler wheel 23 anduponboth si es thereof, so as to engage the edgesof the bucket line and thusretain andguide the line upon the periphery of the idler wheel.

With the slaek portion of the bucket line suspended by the idler wheel23 as shown in Figs 1 and 2, the bucket line sags along two catenarycurves, and the descending buckets are kept relatively close to theladder. A large portion of the weight of the buckets in the slackportion of the line is carried by the idler wheel 23 and thus asubstantial amount of strain is removed from the connecting links andpins of the buckets. Therefore with my invention it is practical toconstruct dredging machines for operating at greater depths than haspreviously been considered feasible. Furthermore the lower end of theladder can be brought comparatively close to the base of pinnacle 22without danger of the bucket line becoming caught as might be the caseif the slack portion were unsupported. The number of buckets draggingupon the formation is also materially reduced with the result that thepower required to operate my dredging machine is substantially less than.with ordinary machines.

I claim:

1. In a dredging machine, a ladder :adapted to extend outwardly anddown- Ward-ly from a-supporting structure, an endless bucket-linesupported by and entrained about said ladder, the upper-portion of saidline being normal-1y tensioned durinig operation, and the lower portionbeing normally slack, an idler wheel journaled upon said ladder andpositioned intermediate between the ends thereof, the slack side ofsaidyli ne being entrained over said wheel so that the outer side of theline rides upon the periphery of the wheel, and guide rollers supportedby said ladder adjacent said wheel and serving as means for guiding theline uponsaid wheel.

2. In a dredging machine, a ladder adapted to extend outwardly anddownward-ly from a supporting structure, an endless bucket linesupported by and entrained about said ladder, the upper portion of saidline being normally tensioned during operation, and the lower portionthereof being normally slack, an idler wheel journaled upon said ladderand positioned intermed-ia-te the ends thereof, the slack portion ofsaid line being entrained over said idler wheel so that the outer sideof the line engages the periphery 'of the wheel, and guide rollerssupported by said ladder adjacent said wheel and serving as means forguiding the line upon said wheel, said guide rollers being journaledupon axes arranged at an angle to the axes of rotation of the pulley.

3. In a dredging machine, a ladder adapted to extend outwardly anddownwardly from a supporting structure, said ladder being formed of apair of parallel structural members secured together in spacedrelationship, an idler tumbler journaled to the lower end of saidladder, driving tumbler journaled at the upper end of 'the angles toladder, an endless bucket line entrained a slack lower portion, an idlerwheel positioned between said structural members and journaled to theladder substantially midway between the ends thereof, the lower portionof the line being entrained over said wheel, and guide rollers mountedupon the inner side of said structural members and adapted to engage theedges of said bucket line near said idler wheel, said rollers beingjournaled on axes arranged at right the axis of rotation of said idlerwheel.

4. In a dredging machine, a ladder adapted to extend outwardly and downewardly from a supporting structure, an endless bucket line supported byand entrained about said ladder, the upper portion of said line beingnormally tensioned during operation, and the lower portion being normally slack, means on, said ladder intermediate the ends thereof forsupporting said line, and means cooperating with said supporting meansfor guiding the line passing over said support means.

5. In a dredging machine, a ladder adapted to extend outwardly anddownwardly from a supporting structure, an end.

less bucket line supported by and entrained about said ladder, theupperportion of said line being normally tensioned during operation, andthe lower portion being normally slack, an idler wheel journaled upOnsaid ladder and positioned intermediate between the ends thereof, theslack side of said line being entrained over said wheel so that theouter side of the line rides upon the periphery of the wheel, and guidemeans cooperatively positioned with respect to said wheel for guidingthe line upon the wheel.

In testimony whereof, I have hereunto set my hand. s

OSCAR B. PERRY.

